A new study from the University of Surrey reveals that solar energy is now the world’s cheapest source of electricity, with production costs as low as £0.02 per unit in the sunniest regions, outpacing coal, gas, and wind. Published in Energy and Environment Materials, the research highlights solar photovoltaic (PV) technology as a cornerstone of the global shift to clean energy.
“Even in the UK, located 50 degrees north of the equator, solar is the most cost-effective option for large-scale energy production,” said Professor Ravi Silva, Distinguished Professor and Director of the Advanced Technology Institute (ATI) at Surrey. “Global solar capacity reached 1.5 terawatts in 2024—doubling since 2020—enough to power millions of homes. Solar is no longer a futuristic dream but a critical part of a sustainable, low-carbon energy future.”
The study also notes an 89% drop in lithium-ion battery costs since 2010, making solar-plus-storage systems competitive with gas power plants. These hybrid systems, combining solar panels with batteries, store energy for release when demand peaks, enhancing grid reliability.
However, challenges remain, particularly in integrating large-scale solar into existing grids. In regions like California and China, excess solar generation has caused grid congestion, leading to wasted energy. “Integrating solar into electricity networks is a key hurdle,” said Dr. Ehsan Rezaee, Research Fellow. “Smart grids, AI-driven forecasting, and improved regional connections are essential to maintain stability as renewable energy grows.”
Innovations like perovskite solar cells could increase energy output by up to 50% without requiring additional land. Yet, consistent policy support is crucial. Programs like the U.S. Inflation Reduction Act, the EU’s REPowerEU plan, and India’s Production Linked Incentive scheme demonstrate how targeted policies can drive investment and innovation.
“Solar, paired with energy storage and smart grids, can deliver reliable, affordable, and clean power at scale,” Professor Silva added. “Sustained global collaboration and long-term policy commitment are vital to accelerate the transition to a resilient energy system.”
Reference: Rezaee E, Silva SRP. Solar Energy in 2025: Global deployment, cost trends, and the role of energy storage in enabling a resilient smart energy infrastructure. Authorea. 2025. doi: 10.22541/au.175647950.09188768/v1
Note: This article is based on preliminary research findings that have not yet been peer-reviewed. Results should be interpreted cautiously. For more details, contact the cited source.
